Global Warming: Out of Sight, Peace of Mind
- March 20, 2015
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The biosphere is the 12.4 mile thick zone of life on Earth represented by the following visual courtesy of The Encyclopedia of Earth.
The oceans make up a large portion of the biosphere with most life occurring in the Euphotic Zone, which reaches to a depth of about 100 meters where light penetrates sufficiently to facilitate photosynthesis. The phytoplankton that thrive on this process are the base of the ocean food chain and the source of the first oxygen to appear in the atmosphere as well as about 50 percent of the current supply of this essential element.
The 7 billion of us who inhabit the planet live on the 30 percent of the biosphere that is land, within the lower third of the atmosphere. The highest inhabited location is La Rinconada,Peru, at an altitude of about 3 miles.
According to UN Atlas: 44 percent of the world’s population lives within 150 kilometers of the sea, which is unremarkable considering life began there and the seas remains a major source of sustenance.
The United Nations projects that by 2100 the global population will surpass 10 billion but these folks will have to support themselves on an even smaller footprint considering it is projected that by then the oceans will have risen by about 1 meter with coastal inundation being the result. This rise will occur due to global warming which is the result of heat being trapped in the biosphere by greenhouse gases. As the Royal Society has pointed out, “Even if human emissions of greenhouse gases were to suddenly stop, Earth’s surface temperature would not cool and return to the level it was at before the Industrial Revolution for thousands of years because CO2 is only removed from the atmosphere over these very long time scales.”
Since warming is already an issue, it should be clear that emissions free energy sources alone do not solve the warming problem.
About 93% of global warming heat is currently being taken up by the oceans, mostly in the upper 100 meters of the tropics, which as discussed here is detrimental to phytoplankton. This heat also produces sea level rise due to thermal expansion and in accordance with the second law of thermodynamics it moves towards the poles where it is melting the icecaps. The Royal Society also points out; more water is likely to be drawn into major rain storms, which could lead to more flooding events.
Although there is considerable uncertainty over changes in hurricanes and tornadoes, the extra energy available may make the strongest hurricanes stronger while dry areas of the subtropics are expected to become even drier in the future.
The Society also states that scientists are: “Very confident. If emissions continue on their present trajectory, then warming of 2.6 to 4.8 °C (4.7 to 8.6 °F), in addition to that which has already occurred, would be expected by the end of the 21st century.”
James Hansen has warned on numerous occasions that 1 °C is the danger limit and that 2°C would be disastrous.
The Royal Society’s Short Guide to climate science offers one ray of hope. In response to the question, “Does the recent slowdown of warming mean that climate change is no longer happening?” it states, “No. Since the very warm surface temperatures of 1998 which followed the strong 1997-98 El Niño, the increase in average surface temperature has slowed relative to the previous decade of rapid temperature increases, with more of the excess heat being stored in the oceans.”
The following diagram from the RSS satellite monthly global mean surface temperature anomaly dataset suggests that no global warming has occurred for 18 years 2 months, since December1996 even though CO2 levels have continued to rise over the same period.
(Remote Sensing Systems (RSS) measurements are satellite datasets of atmospheric temperatures and although the atmosphere absorbs only about 2.3% of global warming heat, these are the temperatures that most impact our lives.)
Since excess heat storage in the ocean is the consensus explanation for this lack of atmospheric warming and the imperative is to keep this warming to 1°C then the facilitation of heat movement into the ocean needs to be, in the interest of self-preservation, our primary objective.
The science of how the heat that is being trapped in the biosphere due to global warming can be distributed or converted from one form to another or to work is defined by the laws of thermodynamics.
The Physics Department of the University of California San Diego points out that the change in entropy (a thermodynamic quantity representing the unavailability of a system’s thermal energy for conversion into mechanical work) of a system ΔS is defined as the amount of energy ΔE added to the system divided by the change in the temperature T of the system (measured in degrees Kelvin),
ΔS = ΔE/T.
Further they state that this is very closely related to the heat capacity of a system or object: “Because entropy and heat capacity are so intimately related, we can instantly order entropies of everyday substances: metals are lowest, followed by stuff like wood and rock, and liquids have the highest (water, especially), on a per-kilogram basis.”
They use the analogy of deep pockets for a system with high specific heat capacity like water and state that, “A system with deep pockets will not increase temperature as much for a given injection of energy. Substances with higher heat capacities have deep pockets, and therefore more ways to spread out the energy internally.”
The oceans are the largest system in the biosphere and are sustaining life by absorbing a great deal of heat but not nearly as much as they could were we to find a way to overcome the natural predisposition of oceans to thermally stratify with the warmest layer remaining near the surface where it in turn influences the atmosphere.
The average depth of the oceans is 4267 meters but only the top 100 meters of the tropics is currently absorbing most of the heat as is evidenced by the mean, upper-ocean, thermal structure along the equator in the Pacific from north of New Guinea to Ecuador calculated from data in the World Ocean Atlas 1998 (Image below from NOAA Pacific Marine Environmental Laboratory).
In essence the oceans are not spreading the energy internally and soaking up enough of the energy being injected into the biosphere to keep us safe in the long run.
This can be overcome with the heat pipe OTEC design explained here, which rather than reducing the amount of energy necessary to support a given amount of economic activity would produce increasingly more climate benefit with every additional unit of energy produced.
The second law of thermodynamics also specifies that in the process of moving heat from a warm to cooler body work, as in the production of electricity, can be produced.
Moving heat that is the fuel for storms into the ocean also reduces sea level rise because that heat can not in turn melt icecaps and the coefficient of thermal expansion of ocean water is less virtually any place in the deep as compared to the tropical surface. At one thousand meters it is half.
Some will claim that burying heat in the ocean is tantamount to sweeping the problem under the carpet.
Scientifically this is not the case because the process in part is a conversion of damaging heat to productive work but in another respect it is producing energy out of sight out of mind as in no one’s backyard. Which is a tremendous advantage considering the sanctity of backyards is becoming an ever increasing impediment to any kind of economic activity at the same time as economic activity that can sustain 10 billion by the end of this century is most needed.